The M&P357 chambered the .357 SIG cartridge favored by several state highway patrol agencies for its retained velocity through vehicle glass. Built on the .40 S&W frame with a .357 SIG barrel and compatible magazines. Type: Pistol Action: Semi-Automatic Caliber: .357 SIG Capacity: 15 Year introduced: 2006, USA Weight: 24.5 oz Overall length: 7.63" Status: Discontinued Intended use: duty, law_enforcement